Automator: update common-files@master in istio/istio.io@master (#11050)

common/.commonfiles.sha

@@ -1 +1 @@
-4f7a47a2619aa100ebdec34dc4a0369204c1c01c
+4023d4ecadf17e8b274212b8c7285ee0e6e9b4fe

common/scripts/check_clean_repo.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# Copyright 2019 Istio Authors
+# Copyright Istio Authors
 
 #   Licensed under the Apache License, Version 2.0 (the "License");
 #   you may not use this file except in compliance with the License.
@@ -14,9 +14,32 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
+function write_patch_file() {
+    if [ -z "${ARTIFACTS}" ]; then
+      return 0
+    fi
+
+    PATCH_NAME="check-clean-repo-diff.patch"
+    PATCH_OUT="${ARTIFACTS}/${PATCH_NAME}"
+    git diff > "${PATCH_OUT}"
+
+    [ -n "${JOB_NAME}" ] && [ -n "${BUILD_ID}" ]
+    IN_PROW="$?"
+
+    # Don't persist large diffs (30M+) on CI
+    LARGE_FILE="$(find "${ARTIFACTS}" -name "${PATCH_NAME}" -type 'f' -size +30M)"
+    if [ "${IN_PROW}" -eq 0 ] && [ -n "${LARGE_FILE}" ]; then
+      rm "${PATCH_OUT}"
+      echo "WARNING: patch file was too large to persist ($(du -h "${PATCH_OUT}"))"
+      return 0
+    fi
+    echo "You can also try applying the patch file from the build artifacts."
+}
+
 if [[ -n $(git status --porcelain) ]]; then
   git status
   git diff
   echo "ERROR: Some files need to be updated, please run 'make gen' and include any changed files in your PR"
+  write_patch_file
   exit 1
 fi